ScienceNOW: Rube Goldberg is alive and well in the climate record. In an effort to explain several spikes in global carbon dioxide (CO2) levels during the last ice age, researchers have come up with the following scenario: Fresh water flooded the North Atlantic Ocean, which slowed ocean circulation, which impeded the transport of nutrients to the ocean’s food web, which starved CO2-consuming organisms that form the basis of that web, which resulted in CO2 buildup in the atmosphere, which eventually …